SOMEDAY, someone is going to make a zero-calorie beer. It’ll look, smell, taste and feel just like the real thing, but it won’t contain an iota of caloric content.

I know this because:

1. The leading segment in the beer world is light – aka diet – beer. People want fewer and fewer calories, even if it means dumbing down the flavor (e.g., MGD 64 and Bud Select 55).

2. It’s possible.

Actually, for years brewers have been saying that it’s impossible. They note, correctly, that the carbohydrates of malt are a primary source of beer calories. Without malt, there can be no beer.

Brewers can reduce those carbs through an extended mashing process or with added enzymes. They can further thin out the content by adding more water.

But you can’t completely eliminate all of the calories, they cry.

“There is no way around it! ” Charles Bamforth, the esteemed professor of brewing science at the University of California-Davis, told me via e-mail. “It is not like Coke and Pepsi where you can replace the calorie source [sugar] with an artificial sweetener. For beer, the main calorie source is alcohol, so no calories means strictly no alcohol. And [to my mind] that ain’t beer! “

Clearly, this is a puzzle that requires some thinking outside the sixpack.

So I called Brian Sherwood. He’s the director of operations at Walden Farms, the New Jersey food company that makes everything from creamy mayonnaise to yummy chocolate sauce with “no calories, fat, carbs, gluten or sugars of any kind! ” If anybody could make zero-calorie beer, it would be him.

“It’s definitely a possibility,” Sherwood said.

As with Walden Farms’ salad dressing and pancake syrup, beer’s main ingredient is water. Some noncaloric ingredient would be added to match the body of beer; artificial color could match the look.

“After that, you have to come up with your flavor profile” Sherwood continued, “a specific type of flavoring, whether it’s the barley or hops. There are probably some beer flavors already on the market. . . . You’d want top notes and bottom notes for a full spectrum of flavor. “

What about the foam?

“You’d have to add carbonation,” Sherwood said. “You’d probably get some little bubbles, but it wouldn’t be a head like a glass of beer. It would be more like the bubbles in soda. “

Unless you used some kind of foam enhancer or stabilizer. Brewers do that all the time. Indeed, hops themselves help promote a healthy collar of foam.

Finally, as Bamforth noted, there’s the alcohol.

One ounce of pure alcohol contains about 200 calories, and there’s about a half-ounce of the stuff in a typical 12-ounce bottle. How do you make a zero-calorie beer with a kick?

Synthetic alcohol.

Researchers at Imperial College London, in England, are working on it now, using chemicals related to the anti-anxiety drug Valium. The substance has the same impact on the brain as alcohol, according to reports that say it provides “a feeling of well-being and relaxation. “

The new alcohol is intended to allow you to drink all night without severe drunkenness or hangovers. The researchers claim that you could even sober up immediately by swallowing a pill, so you could drive home without being pulled over for DUI.

But does it contain any calories?

I checked with the lead researcher, David J. Nutt, and he replied with the good news: “The alcohol substitute would have no calories. Another benefit. “

So, there you have it. Someday, someone is going to make a zero-calorie beer.

Which leaves only two questions:

1. Would you drink it?

And . . .

2. What do you call it?

I kind of like the sound of No-Weiser!

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